This douchebag sped up from behind me so I wasn't able to get over. When I finally did get over, he slammed on his breaks in front of me for zero reason, and I had to swerve into another lane so I didn't wreck into him. At this point we we're at a stoplight, and he rolled his windows down on from and back passenger sides, and started screaming profanities at me and flipping me off. I continued on, contacting police whilst next to his vehicle. He heard me on the phone call through my car Bluetooth, and sped up to about 70 in a 40. He is a dangerous driver.